Steam heating system



y 14, 1964 E. w. MOORE 3,140,824

s'rmu HEATING SYSTEM Filed Aug. 25. 1958 2 Sheets-Sheet 1 no v. THERMOSTAT TRANSFORMER 58 6A8 LINE INVENTOR. EVERETT W. MOORE iwgaw AGENT July 14, 1964 E. w. MOORE 3,140,824

s'rmu HEATING SYSTEM Filed Aug. 25, 1958 2 Sheets-Sheet 2 98 9e 94 1 4 "o 94 39 I06 34 I04 TI] as INVENTOR.

EVERETT W. MOORE AIIIT United States Patent Ofice 3,140,824 Patented July 14, 1964 3,140,824 STEAM HEATING SYSTEM Everett W. Moore, 3837 E. Glenrosa Ave., Phoenix, Ariz. Filed Aug. 25, 1958, Ser. No. 757,153 1 Claim. (Cl. 237-17) This invention relates to a heater and more particularly to a heater of the steam radiator type including a boiler and condenser system which is hermetically sealed and wherein vapors are maintained at a pressure considerably below atmospheric pressure.

Various steam heaters of the prior art have utilized condenser and boiler systems wherein vapors are operated at pressures below atmospheric pressure. However, most of these systems have utilized a vapor pump to return. the fluids from the condenser or radiator to the boiler. Such vapor pumps are necessary in systems wherein a great temperature differential may occur in the conduits thereof which extend considerable distances from the boiler to the radiators or condensers. Systems of the prior art vent to the atmosphere and include various means for adding makeup water thereto. Such features are generally necessary in a system which is designed for heating a number of rooms which may be located at different elevations in a building and disposed considerable distances from the central steam plant.

The present invention is distinguished from a prior art in that it relates to a very compact steam boiler and condenser or radiator unit in a hermetically sealed system which does not have any makeup water inducing devices or any atmospheric vents and further does not include any vapor pumps to transfer fluid from the 'condenser or radiator to the boiler.

Accordingly it is the object of the present invention to provide a very simple and compact steam heating system which may be used in small, confined spaces to induce heat into a duct or central air conditioning system of a dwelling or the like.

Another object of the invention is to provide a steam heating system which is very small and compact in proportion to its heat transfer capacity.

Another object of the invention is to provide a steam heating system which is very safe for reasons that it contains a very small amount of water and that fiuid pressure in the system is very low.

Another object of the invention is to provide a steam heating system which, due to its compactness, low working pressure and small water supply delivers heat very quickly to its condenser or radiator after heat is applied to the boiler thereof.

Another object of the invention is to provide a steam heating system which, due to its compactness, low operating pressure, and small water supply is capable of accurately maintaining a desired temperature in a building without complicated controls such as temperature anticipating apparatus.

Another object of the invention is to provide a steam heating system wherein a small amount of wateris used at a pressure whereby the system delivers heat very quickly and cools down very quickly due to a low thermal capacity of the system, thereby obviating the necessity of controls which are ordinarily used to compensate for the thermal lag of a heating system when it is turned on and off.

Another object of the invention is to provide a steam heating system which is very efiicient due to its compact construction and high temperature differential between the heating medium and the vapor in a system which is accomplished by low operating pressure at which vapor is produced.

Another object of the invention is to provide a small, compact steam heating system which is very safe due to a novel combination of controls which includes temperature and pressure sensing electrical switches coupled to a solenoid valve to control the inlet of fuel to a burner which heats the burner of the system.

Another object of the invention is to provide a steam heating system wherein a pressure relief valve vents to a burner compartment of the boiler of the system whereby excessive pressure in the system passes steam to blow out the burner flame and pilot light whereby a safety valve coupled with the pilot burner automatically shuts off the fuel gas to the burner.

Another object of the invention is to provide a very simple and compact steam heating system wherein the gas-fired boiler may be located remotely from a condenser which is coupled to the boiler thus preventing any possibility of gas fumes from mingling with air heated by the condenser.

Another object of the invention is to provide a steam heating system wherein a boiler may be remotely positioned relative to the radiator or condenser so that the gas burner used to heat the boiler \may be positioned on the outside of a building room thereby reducing the hazards of fire and gaseous asphyxiation.

Another object of the invention is to provide a steam heating system which is very simple and easy to maintain.

A further object of the invention is to provide a steam heating system which is hermetically sealed wherein a small amount of water is used at sub-atmospheric pressures thereby obviating the possibility of mineral deposits collecting in the boiler or the system.

Another object of the invention is to provide a compact steam heating system which may be assembled as a unit whereby the condenser thereof may be placed in a duct of an airconditioning system and the burner together with its controls may remain directly attached thereto.

A still further object of the invention is to provide a small, compact steam heating system which is capable of transferring 25,000 B.t.u. or more per hour when utilizing only a pint of water.

Further objects and advantages of the invention may be apparent from the following specification, appended claim and accompanying drawings in which FIG. 1 is a diagrammatic illustration of a steam heating system in accordance with the present invention and showing some features of the invention in section.

FIG. 2 is a side elevation view of a steam heating system in accordance with the present invention and showing the same all connected together by a unitary frame which supports the condenser of the system in an airconditioning duct; and

FIG. 3 is a sectional view taken from line 3-3 of FIG. 2.

As shown in FIG. 1 of the drawings, a tubular boiler 10 is contained in a boiler housing 12 having a burner 14 in lower portion thereof. The burner 14 is a natural gas burner, or any other suitable means for applying heat to the boiler 10 may be used.

The particular boiler 14 is provided with a conventional pilot 16 coupled to a conventional safety valve 18 which shuts off the supply of gas by a conduit 20 to the burner when the flame pilot 16 is blown out.

The burner housing is provided with access door 22 which is a conventional door utilized to service the bumer 14 and pilot 16.

An exhaust gas chimney 24 communicates with the upper end of burner housing 12 and extends into a conventional down draft diverter 26 communicating with chimney 28. V

The boiler 10 is provided with an inlet tube 30 at its lower end and an outlet tube 32 at its normally upper end. When heat is applied by means of the burner 14,

Q water in the helical tubular structure of boiler is boiled and steam passes outwardly through the conduit 32 and into a tubular condenser 34 having an inlet 36 at its upper portion and outlet 38 at its lower portion which communicates with the boiler inlet 30. The condenser outlet 38 is disposed at an elevation considerably above the boiler inlet 30 and the lowermost portion of the boiler.

A pressure equalizer conduit 40 intercommunicates with the conduit 32 and the conduit 38 at a level considerably above the inlet conduit 30 of the boiler. This pressure equalizer tube is provided with a liquid trap portion 42 which is disposed below outlet 38 of the condenser. The condenser coil 34 is provided with fins 4 disposed to extend the surface area thereof for efilcient heat transfer when air is forced thereover by a fan 46 driven by a motor 45. The fan 46 and motor 48 may be the equivalent of a motor-driven blower in the conventional air conditioning system in which the structure of the present invention is shown in FIGS. 2 and 3.

The system comprising the boiler 10, conduit 32, condenser or radiator inlet 36, condenser 34, condenser outlet 38, burner inlet 32, and pressure equalizer tube 40 are charged with a small amount of Water at the pressure considerably below atmospheric pressure.

For example, when the system is designed for a heat transfer capacity of 25,000 B.t.u. per hour the system may be charged with a pint to a quart of water. The system is preferably operated on one pint of water as will be hereinafter described. The heat transfer capacity of the condenser coil 34, when under air flow induced by the fan 46, should be great enough to maintain a condenser temperature of 201 degrees F. which will maintain the boiler at 6 inches of water vacuum.

The boiler, when the burner fire is off, should have an internal pressure of 22 inches of water vacuum. Under these conditions, when the boiler is heated, steam will be created at 20 inches of water vacuum and at 161 degrees F. whereby the pint of water in the system is very quickly converted to steam heat which travels through the condenser 34.

A blow-oft or pressure device 5'0 is set to relieve pressure internally of the system at a predetermined pressure of 12 pounds per square inch. This pressure relief device communicates with a tube 51 which is directed i11- ternally of the burner housing 12 and toward the burner 14 and pilot 16. Steam from the interior of the system released by rupture of an element of the device 50 thus flows into burner compartment thereby blowing out the flame of the burner and the pilot 16. Normal operation of pilot generator temperature safety valve 18 will then cause the gas supply to be shut off and no further gas will flow through the tube 26 to burner 14.

An electrical pressure switch 52 senses pressure internally of the conduit 32 and this pressure switch is coupled in series with a high temperature sensing electrical switch 53 which senses temperature of the conduit 32 in close proximity to the boiler 10. Another electrical thermal switch 54 is connected in series with the switches 52 and 53 and this switch 54 is disposed in close proximity to the condenser 34 and located thereabove.

The switches 52, 53 and 54 are coupled in series to control a solenoid valve 55. Electrical power for such control is provided by means of a transformer 56 which receives power from a 110 volt line 57.

A conductor 58 extending from the transformer is coupled to a thermostat 60 which is disposed to sense the temperature of a room being supplied heat by a heating system of the present invention.

A thermostat 6 is connected in series with the electrical switch 53 by means of a conductor 62 while connectors 64 and 66 interconnect the switches 53 and 52 and switches 52 and 54 respectively. A conductor 68 is coupled to the switch 54 and extends to a terminal 70 solenoid valve 55. Thus the thermostat 60, switches 52,

ass,

d 53 and 54 are all coupled in series to the connector 68 and the terminal '70 of the solenoid valve 55.

Coupled to a terminal 72 of the solenoid 55 is a conductor 74 which is coupled to a terminal 76 of the transformer 56. Thus a low voltage circuit is provided for operation of the solenoid valve by means of the switches 52, 53, 54 and the thermostat 60 all in series with each other.

The switch 52 is a fluid pressure sensing switch which is operable to shut off the solenoid valve 55 whenever pressure in the system exceeds approximately 4 pounds per square inch.

The high temperature switch 53 in close proximity to boiler 10 operates at a high temperature, when the fan 46 fails to exchange heat from the condenser 34 which causes the boiler to heat up excessively. If the fan 46 fails for any reason and the boiler heats to an excessively high temperature, the switch 53 shuts off the solenoid 55 valve and stops operation of burner 14.

The switch 54, adjacent to condenser 34, also senses an increase of temperature in the system in the event the fan 46 fails. This switch 54 is an added safety device which is disposed to shut off the solenoid valve at a temperature which corresponds to a pressure substantially lower than blowoff pressure at which the pressure relief device 0 operates. Normally the pressure relief device 50 will come into operation before temperature of the boiler becomes sulficiently high to actuate the switch 53.

The motor 4-8 receives electrical power through conductors 76 and '78 coupled to a relay 80 which receives power from the line 5'7. Conductors 32 and 84 are coupled to the conductors 62 and 74 whereby the thermostat 60 controls operation of the motor 48 as well as that of the solenoid valve 55. Thus the motor 14 and fan 46 are concurrently turned on and off by the thermostat 60 .in accordance with room temperature in which air is being supplied by the heating system of the present invention.

It will be appreciated by those skilled in the art that one pint of water in the system of the present invention when operating at sub-atmospheric pressures will move very rapidly from the boiler through the condenser and back to the inlet of the boiler.

While the pressure equalizer tube 40 is intended to equalize pressure from the inlet to the outlet of the boiler and the condenser, a slight pressure differential is provided by the trap loop 42 of the equalizer tube 40 so that flow of vapor normally passes into the inlet 36 at the upper portion of the condenser.

It has been found that the elevation of the condenser outlet 38 above the boiler inlet 30 provides for a very quietly operating system.

As shown in FIG. 2 of the drawings, the boiler housing 12 is supported by a bracket 86 which extends from a frame 88 in which the condenser 34 is mounted.

The frame 83 surrounds the condenser 34 and supports the same and provides means for placing the condenser in an air conditioning duct. As shown in FIG. 3 of the drawings, the frame 88 is substantially channel shaped in cross section whereby it is provided with a pair of flanges 90 and 92 to which flanges 94 and 96 of duct sections 98 and 100 are secured.

Internally of the frame 88 are angle members 102, 104, 106, and 108 which provide lateral support for the loops 35 at opposite ends of the condenser coils. Thus, the condenser is secured internally of the frame 88 so that it may readily be placed and retained in position internally of an airconditioning duct formed by the duct sections 98 and 100. It will be seen that the frame 88 forms a short section of an air-conditioning duct and supports the condenser 44 therein.

The bracket 86 is fitted and secured in the channel shaped structure of the frame 88 and is provided with a pair of parallel bracket plates 110 and 112 which are integral with an intermediate portion through whichbolts 114- extend. These bolts are screw threaded in the I burner housing 12 and rigidly support the burner housing 12 together with the boiler in unitary rigid assembly with the frame 88 and the condenser 34.

As disclosed in FIGS. 2 and 3 of the drawings, it will be apparent to those skilled in the art that the steam heating system of the present invention may be very small and compact and also versatile of installation. For example, a wall as shown by dash lines A may be disposed between the boiler housing 12 and the condenser 34 so that the boiler and burner may be outside of a building room wall while the condenser may be inside. Further, it will be appreciated that the structure of the present invention is very adaptable to installation in existing airconditioning ducts or into conventional refrigeration systerns.

All of the tubular conduits of the present system are made of copper and for this reason the condenser 34 may be located either upstream or downstream of a conventional refrigerant evaporator coil. Condensation from the coil will not cause deterioration of the copper heating coil of the present invention. Furthermore, the heat supplied by the condenser 34 is extremely desirable since it is clean and remote from any gas used to heat the steam pouring therethrough.

When an installation is made as shown in FIGS. 2 and 3 of the drawings with the burner outside of the building room Wall, the hazard of fire and asphyxiation are greatly reduced and heat is supplied in a highly desirable manner by steam flowing through the condenser 34.

It will be obvious to those skilled in the art that various modifications of the present invention may be resorted to in a manner limited only by a just interpretation of the following claim.

I claim:

In a heater the combination of: a hermetically sealed system comprising a boiler; means for heating said boiler; a condenser; second means for exchanging heat from said condenser; a first conduit intercornmunicating with upper portions of said boiler and said condenser; a second conduit communicating with lower portions of said condenser and said boiler; said second conduit forming a liquid return passage from said condenser to said boiler; and heat exchange liquid in said system at a pressure considerably below atmospheric pressure, said liquid of a volume which will convert to steam at the upper portions of said boiler and condenser at a temperature below the ambient pressure boiling temperature of the liquid, said heat exchange liquid ranging from 1 pint to 1 quart by volume for energy equal to 25,000 B.t.u.s per hour ex changed from said condenser.

References Cited in the file of this patent UNITED STATES PATENTS 1,498,857 Shoonmaker June 24, 1924 1,783,428 Jennings Dec. 2, 1930 2,155,255 Crago Apr. 18, 1939 2,234,869 Loveless Mar. 11, 1941 2,276,093 Robbins Mar. 10, 1942 2,360,665 Fields Oct. 17, 1944 2,434,575 Marshall Jan. 13, 1948 2,522,373 Jodell Sept. 12, 1950 2,600,252 Long June 10, 1952 2,789,769 Dalin Apr. 23, 1959 2,868,461 Gaddis Jan. 13, 1959 

